Firearm.



Patented Mar. 25, |902.4

0. C. CULLEN.

FmEAnM l 2 Sheets Sheet I.

(No Model.)

/WTEST- Aare cross-sections. I5

linthe wall-of the cylinder.

UNITED STATES ORLAN CLYDE CULLEN, OF lVA PATENT OFFICE.

TERLIOK, VIRGINIA, ASSIGN OR TOELIZA- -'BE' IH DOUGLAS CULIiEN, OF INATERLICK,- VIRGINIAMAND. EDWARD. QVILLOUGHBY AN DERSON, OF WASHINGTON, DISTRICT OF COLUMBIA.

FIREARM.

SPECIFICATION forming part of Letters Patent 1\lo.'696,318, dated March 25, 1902. Applcationiiled December 14, 1899. Serial No. 1740,318. (No model.)v

To all Iwil/m, zit may concern: A

Be itknown that I, ORLA'N CLYDE CULLEN, a .citizenof the United States, 'residing a-t Wa- ,ter1ick, in the count'yof lVar-ren and State'of Virginia', have invented certain new and use- .fullnrprovements in Firearms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art-to which it appertains to make andpusethe same.

In the drawings, Fignrel is a eide view of a gun. Fig. 2 is a central longitudinal section showing the invention. Figs. A3 and 4 tion of the muzzle portion. Fig. 6 is a detail view. v The invention relates to firearms; and it consists chiefly in providing the cylinder of thejborewith ball-bearings having a spiral arrangement in suitable seats of the cylinder.

The invention further consists in combining -with the ball-bearings and their grooveseats a recoil-cushion; and, finally, the invention consists in the combinations offparts hereinafter set forth. Y

In the accompanying drawings the invention is shown in connection with a cannon of -rifle character or designed to give rot-ary Inlo- -tion to the projectile.

'luder portion of' thegun or part in front of The letter A designates vthe barrel or cylvthe chambered breech,and B B indicate spiral inclosinggrooves,preferably of uniform twist These grooves are equidistantand in number usually eight, althou'gh'a greater or less number may be 'employed,if desired. Each groove is in crosssection bounded by the greater arc of a circle and communicates with the bore bya slot C, which is of 'comparatively small transverse extent or narrovvwith relation to the dialneter of the cylindrical groove'. Each spiral cylinder-groove is therefore formed in the wall -of the boreand communicates'with the latter by its narrow spiral slot, as indicated.

AIn practice it is preferable to bore the cylinder-groove through from end to end of the barrel and to close the ends of the groove. This may be accomplished by providing the Eig. is an enlarged sec` are designed to project from thesame th ythe slots'C by a small portion of the supera spring or glycerinrecoil-cushion `L, the lat-v ter being preferred;

.K is a' cylinder slide or piston 'arranged in ltheseat Gnext the series of ball-bearingsH and in rear of the glycerin'cushion. These ball-bearings'are of hard steelof true"` spherical formand when inposition in lthe grooves rough ficies, -usually one-twentieth of the diameter. The balls t the groove ratherneatly, there being sufficient tolerance4 toallow rotation.

- lThe projectile preferred for use in jections or flanges, as y-it is designed to engage the projecting portion of the ball-beau' ings, this hengagement being in the nature of elastic pressure, which is set up by the elasticity of the steel balls ofthe body of the cannon and of the projectile itself. In order to secure this elastic pressure, thev diametric distance between the bottoms of opposite grooves is' made equal to or rather slightly less than the diameter of two ball-bearings and the diameter of the projectile. When the projectile is provided .a's indicated, the best results are attained in range and accnracy, as well as in the duration of the piece. For the best results for accuracy the projectile should be made a tight tfor the ball-bearings, and as these ball-bearings have only a slight projection into the ,bore when the projectile is passing through the bore its surface approximates very 'closely contact therewith.

When the glycerin-cushion is used, the muzzle end of the groove is usually provided this gun'V is made with a cylindrical body, without pro- `lprovided with with a cylinder or plates forming a cylinder of smaller diameter than the groove, and the glycerin is placed therein. The piston is usually shouldered and made concave at the rear end to receive the face of the end roller or hall. y

Having described this invention, what I claim as my invention, and desire to secure by Letters Patent, isl

1. A gun having, in the wall of its bore spiral inclosing grooves carrying ball-bearings, substantially as specified.

2. A gun having, in the wall of its bore, spiral grooves, carrying ball-bearings, and

recoil-cushions at their forward ends, substantially as specified.

3. A gun having, in the wall of its bore spiral grooves of circular cross-section conimunicating with the bore by comparatively narrow spiral slots, substantially as specified.

4. A gnn having, in the wall of its bore, spiral grooves olf-circular cross-section, terminating in cushion-seats at'their forward ends,

and communicating witlrtho bore hy comparatively narrow spiral slots, substantially as specified.

5. 'A gun having its cylinder-wall provided with spiral-inclosing grooves, and their slots off-communication, the recoil-cushions at the ends of said grooves, the the screw-cap or stop at the ends of the grooves, substantially as specified.

6. In. av gun, the combination with inclosing grooves or seats in the cylinder, of ball bearings projecting slightlyfrom said grooves or seats, substantially as specified.

7. A gun having the bore provided with grooves or seats, and in such grooves or seats,

rotary bearings adapted to engage a smooth Y cylinder projectile in its passage through said bore, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

ORLAN CLYDE CULT. 1N.

\Vitnesses:

GEORGE M. ANDERSON, HARRY L. AMER.

ball-bearings, and v 

